+1 - Borla Stingers....I voted for Dynomax because my dd has Dynomax race bullets on it, but Borla Stingers are by far, the best sounding muffler I've ever heard....Especially when Kooks L/t. and a Kooks o/r x is used.
Have the Steeda catback with the bassani x pipe and it sounds incredible. Get compliments on it all the time. Friends with stangs have commented on how it drowns theirs out when they follow us. Never cared for the sound of the flowmasters so I went for something different and haven't regreted it yet.